similar to: Difficulty with LRSM Rasch analysis with eRm package in R.

Dear R Users, I am using the LLTM and the LRSM functions in the eRm package to do repeated measurements where there are 2 measurement points for a list of 10 items. I am trying to get ability estimates but am having trouble. I don't think that it is appropriate to use the pmat function since the person parameters are based on all 20 items. Rather, I think it would be more appropriate to

I'm trying to kick off some of the rust and learn some of the R packages for Rasch modeling. When I tried using the eRm package, I get item difficulty estimates for all my items accept the first (in terms of order) item. #Begin code library(eRm) r.simulation <- sim.rasch(20,100) r.data <- r.simulation$items #eRm results erm.rasch <- RM(r.data) names(erm.rasch) erm.items <-

When I try to create a Rasch simulation of data using the sim.rasch function, I get more items than I intend #My code library(eRm) #Number of items k <- 20 #Number of participants n <- 100 #Create Rasch Data #sim.rasch(persons, items, seed = NULL, cutpoint = "randomized") r.simulation <- sim.rasch(n,k) I end up with 20 participants and 100 items, but the instructions say

I use the following function to select a subgroup from a data vector (usually to calculate descriptive stats). select.range<-function (groupvec, min, max, data) { if (nargs() > 3) { min.cond <- groupvec >= min max.cond <- groupvec < max cond <- min.cond & max.cond selected <- na.remove(ifelse(cond, data, NA))

Hi guys at mapstraction, I made a change in the Polyline.toMicrosoft() function, in order to have all the power that a VEShape has, for instance fill color. Below is the new code, if you want to use it, change it, or whatever. Cheers, Beta /** * toMicrosoft returns a Microsoft polyline * @returns a VEShape */ Polyline.prototype.toMicrosoft = function() { var mpolyline; var mpoints

Hi! I have large matrices, one column per variable and I have a vector of factors / grouping symbols. Then I am computing subtotals for the groups but it takes pretty long and thus I wanted to ask if there is a better way to do it or if this is already the best way: subTotals <- function(x, groupvec) do.call("rbind",lapply(split(x,groupvec),colSums,na.rm=T)) Thanks reading my

I'm testing an education assessment (evaluating quantitative skills in biology students) for reliability. I used cronbach's alpha, but got a really low alpha which I think is likely due to my small number of questions (12) and the fact that the questions are of varying difficulty. After a lot of reading, it looks like Rasch models are probably a more appropriate tool for my question so

I'm new to 'R', so forgive me if I've used the wrong term. I'd like to model some Likert-style items using Rasch methods. I've been unable to find mention of these for 'R'. Would someone happen to know of any? Thanks in any case. Bill ------------ "It is the time that you have wasted for your rose that makes your rose so important."--St-Exupery

Dear useRs, new and updated features in eRm 0.9-6 for extended Rasch modeling: - infit and outfit mean-square statistics added to functions personfit() and itemfit(). - new method: plotPImap() plots a person-item map (cf. Bond & Fox, 2007), i.e., a map of locations of item (and threshold) parameters, and the distribution of person parameters. - new options in plotGOF(): 'conf':

Dear useRs, new and updated features in eRm 0.9-6 for extended Rasch modeling: - infit and outfit mean-square statistics added to functions personfit() and itemfit(). - new method: plotPImap() plots a person-item map (cf. Bond & Fox, 2007), i.e., a map of locations of item (and threshold) parameters, and the distribution of person parameters. - new options in plotGOF(): 'conf':

Hi I don't know where the announcements go. I cloned https://git.centos.org/git/rpms/kernel.git and grabbed the changelog section pasted below from the git diff in SPECS/kernel.spec (commit dated 4 Feb 2020) Regards +* Thu Dec 12 2019 Frantisek Hrbata <fhrbata at hrbata.com> [3.10.0-1062.12.1.el7] +- [powerpc] powerpc/pseries: Remove confusing warning message (Gustavo Duarte) [1780148

Hi, I am running the non-parametric rasch model tests using eRm. I have a reasonably large dataset for this type of exercise (110 items, 248 persons). I run: > allb2=as.matrix(allb) > rsample <- rsampler(allb2, ctr) > t102<-NPtest(rsample, method="T10") #global test, subgroup inv and receive error message as follows. "Error in m[idx1, idx2] <- 1 : subscript out

Hi list, I tried to load the package SAGx and failed because it complains it's looking for the Biobass which is not there. Then I looked up the package list and Biobass is not found. I'm trying to run the Jonckheere-Terpstra test and from what I see in the R archive, SAGx is the only place it's been implemented. > library(SAGx) Loading required package: multtest Loading required

Hello all, I have just started using fitting the PCM (Partial Credit Model) using eRm and have 2 problems which I cannot solve, I have checked everywhere on the net, but no joy: Firstly, I have fit a PCM model to 10 variables with differing response categories (3 for the first 6 items, 4 for the following 2 and 2 for the last two items). mat1 <- matrix(c(rasch_bart$bart_bowel,

Dear R-List, I tried to fit a partial credit model using the "pcmdat" from eRm-package comparing the results of mirt, eRm, ltm and winsteps. The results where quite different, though. I cannot figure out what went wrong and I do not know which result I can rely on. This is what I did in R library(mirt) #load(file="u3.RData")

Hey people, I''m starting a new project and just finished creating the ERM diagram with about 30 tables. There are quite some tables with foreign keys so I''m not sure how to start creating the controllers/models. How should I start creating controllers/models? Should I first create all tables without foreign key? Should I just start somewhere and add them radomly? I''m

I am working on setting up a Puppet configuration where some of the data is stored on a DRBD volume. The modules and vardir are stored on the drbd volume. The puppet.conf files point to the drbd volume for vardir. I created a cert for a VIP puppet-master using the puppetca -- create command I had everything working on the primary drbd node, but when I fail over, everything starts up fine, but I

On our CentOS 7 servers I see there is a new kernel available when doing yum update: kernel 3.10.0-1062.12.1.el7 kernel-devel 3.10.0-1062.12.1.el7 However I am not able to find any announcement at redhat.com for this kernel. The only announcement I find is this from CentOS: https://www.mail-archive.com/centos-announce at centos.org/msg11573.html However that CentOS announcement links to

This is a very basic question, but I am a bit confused with optim. I want to get the MLEs using optim which could replace the newton-raphson code I have below which also gives the MLEs. The function takes as input a vector x denoting whether a respondent answered an item correctly (x=1) or not (x=0). It also takes as input a vector b_vector, and these are parameters of test items (Rasch estimates

Dear all, I'm working on ability estimates using Rasch model. Using the "ltm" package, the procedure is quite simple: ## Factor Scores for the Rasch model fit <- rasch(LSAT) factor.scores(fit) What about Partial Credit Model (PCM)? For PCM I use PCM function from eRm package. Is there any similar function like factor.scores to estimate ability scores using PCM model? Best,